常用的函数，目前有下面几个，待增加

round_qsw(number,power=0)
intToFloat_qsw(v:int,tag=4)
floatToInt_qsw(v:float,tag=4)
checkSum_qsw(arg:str,byteorder='little')
hexToAsc_qsw(arg:str)
ascToHex_qsw(v:str)

 

def round_qsw(number,power=0):
    """
    实现精确四舍五入，包含正、负小数多种场景
    :param number: 需要四舍五入的小数
    :param power: 四舍五入位数，支持0-∞
    :return: 返回四舍五入后的结果
    """
    digit = 10 ** power
    num2 = float(int(number * digit))
    # 处理正数，power不为0的情况
    if number>=0 and power !=0:
        tag = number * digit - num2 + 1 / (digit * 10)
        if tag>=0.5:
            return (num2+1)/digit
        else:
            return num2/digit
    # 处理正数，power为0取整的情况
    elif  number>=0 and power==0 :
        tag = number * digit - int(number)
        if tag >= 0.5:
            return (num2 + 1) / digit
        else:
            return num2 / digit
    # 处理负数，power为0取整的情况
    elif power==0 and number<0:
        tag = number * digit - int(number)
        if tag <= -0.5:
            return (num2 - 1) / digit
        else:
            return num2 / digit
    # 处理负数，power不为0的情况
    else:
        tag = number * digit - num2 - 1 / (digit * 10)
        if tag <= -0.5:
            return (num2-1)/digit
        else:
            return num2/digit


"""
    实现求校验和功能
    :par arg:字符串形式如‘00 01 02' 或 '000102' 必须是偶数位
"""
def checkSum_qsw(arg:str,byteorder='little'):
    arg=arg.replace(" ","")
    leng=len(arg)
    if(leng%2!=0):
        raise Exception("arg length is not even numbers!")
    checksum=0
    leng//=2
    for i in range(0,leng):
        t=arg[2*i:2*i+2]
        #print(t)
        x=int(t,16)
        checksum +=x
    checksum=checksum%256
    return hex(checksum)

"""
    实现转换浮点型内存格式
    :par float:字符串形式如‘00 01 02' 或 '000102' 必须是偶数位
    :par tat 几个字节 默认8个字节
    :return 16进制格式
"""
def floatToInt_qsw(v:float,tag=4)->int:
    import ctypes as c
    _floatTYPE = c.c_double if tag is 8 else c.c_float
    _intTYPE   = c.c_ulonglong if tag is 8 else c.c_int   
    if isinstance(v,float):
        v_float = _floatTYPE(v)
        ptrTYPE = c.POINTER(_intTYPE)
        ptr = c.cast(c.pointer(v_float),ptrTYPE)
        return hex(ptr[0])
    elif isinstance(v,int):
        v_int = _intTYPE(v)
        ptrTYPE = c.POINTER(_floatTYPE)
        ptr = c.cast(c.pointer(v_int),ptrTYPE)
        return hex(ptr[0])
    else: 
        return hex(v)

"""
    实现转换内存格式整型转浮点型 4个字节
    :par float:字符串形式如‘00 01 02' 或 '000102' 必须是偶数位
    :par tat 几个字节 默认4个字节
    :return 16进制格式
"""
def intToFloat_qsw(v:int,tag=4):
    import struct
    ba=v.to_bytes(tag, byteorder='big', signed=True)
    return struct.unpack("!f",ba)[0]
"""
    字符串转16进制
    quanshiwei =  '7175616e736869776569'
"""
def ascToHex_qsw(v:str):
    v=v.replace(" ","")
    r=''
    for tmp in v:
        t=hex(ord(tmp))
        r+=t[2:]
    return r

"""
    asc16进制转字符串
     '7175616e736869776569' = quanshiwei
"""
def hexToAsc_qsw(arg:str):
    arg=arg.replace(" ","")
    leng=len(arg)
    if(leng%2!=0):
        raise Exception("arg length is not even numbers!")
    checksum=''
    leng//=2
    for i in range(0,leng):
        t=arg[2*i:2*i+2]
        hexI=int(t,16)
        x=chr(hexI)
        checksum +=x
    return checksum